This invention is directed to pulp refiners, and, more particularly, to the mechanism used for attaching a refining plate to its supporting head.
Some refiners for wood pulp or the like, have stationary refining plates that flank rotary refining plates in the chamber of a housing whose inlet admits stock for treatment by comminuting projections (e.g., ribs) on the neighboring surfaces of stationary refining plates and rotary refining plates. Currently, the set of refining plates that are mounted to the rotating and stationary heads use four or more fasteners for each refiner plate. Mounting holes are normally located in the refining area of the plates, thus reducing the useful refining surface. The plates fit against an outer ring at the outside diameter of the head. The outer ring contains the plates in proper location and prevents outward movement due to centrifugal forces. The fasteners are designed to carry all the torsional forces acting on the refiner plates that occur during operation, while the outer ring carries all the centrifugal forces. In setting the plates against the outer ring, the plates are equally spaced around the head in the circumferential direction, with minimal space between each plate. However, due to manufacturing tolerances, openings can be created between the plates, and these openings can result in corrosive or erosive attack on the head mounting surfaces. Installing or replacing plates is very time consuming, and is dependent on the number of fasteners that need to be removed or installed.